The invention relates to an attachment mechanism and system used to accessorize, customize and/or personalize footwear with interchangeable uppers or straps, especially open shoes and sandals. More particularly, this invention presents a safe, secure and easy system for the attachment and detachment of shoe uppers and straps to shoes and sandals. This invention allows both the manufacturer and wearer to promote and display fashion and theme material of their own choosing, with the freedom to change the material or message without having to change footwear or specifically without having to change the sole portion of the footwear.
Footwear tends to be relatively expensive, and is often chosen to match particular items of dress. A plethora of dress items is usually matched to a much smaller universe of available footwear, so that the footwear is chosen in basic colors and styles to coordinate with a larger universe of dress items. Footwear is also purchased according to season, degree of formality and heel height, with sandals and open-toed shoes predominating in the warmer months. Coordinating even this limited selection with wardrobe items can be difficult, and it is too expensive to purchase a new pair of shoes or sandals for each ensemble. The invention also allows a large variety of footwear to be stored in a much smaller space due to the variations available with each sole portion.
Accordingly, the desirability of footwear with convertible style has been appreciated. The prior art has propose numerous solutions, including those set out in U.S. Pat. No. 4,839,948 to Boros, which is incorporated by reference herein for all purposes. As noted in Boros, the concept of replaceable uppers is well established, wherein a sole is provided with a plurality of interchangeable uppers. Typically the sole is in a basic or neutral color, whereas the uppers are supplied in an array of colors and designs. Using a system of interchangeable uppers with a single base shoe unit, the user can have a pair of shoes that compliment a variety of apparel for reduced cost.
The prior art, however, has not provided an entirely satisfactory solution to the problem of easily attaching and detaching the uppers to the sole with a minimum of inconvenience. Other problems ensue where the sole portion or the entire shoe must be specially manufactured to accommodate the removable uppers. Further problems occur when manufacturing complex mechanisms to attach and detach the uppers, or mechanisms that require the application of special tools. Another problem is the appearance of the attachment mechanism itself. A single, distinctive piece, if perceptible on the outside of the shoe, may conflict with the uppers and the overall appearance of the footwear, defeating the one of the basic purposes of interchangeable footwear.
Accordingly, it is an object of the present invention to provide improvements in the attachment system for convertible footwear.
Another object of the invention is the provision of an improved engagement means for detachably securing the upper portion or strap to the sole of the shoe or sandal.
Another object of the invention is to provide engagement means that are readily and conveniently usable by the wearer.
Another object of the invention is the provision of engagement means that will reliably and securely affix the upper to the sole and provide sufficient load bearing capacity to offset the upward pressure of the instep of the wearer on the shoe upper.
Another object of the invention is the provision of attractive and easily matched engagement means.
Another object of the invention is the provision of a releasable fastener in the form of a separately manufactured clasp that can be used with otherwise conventional footwear.
Another object of the invention is to provide a fastening system that allows for various configurations of straps on a single sole portion.
Another object of the invention is to provide a fastening system that allows interchangeable straps for different heel heights, adapted for the specific load bearing necessity of the particular footwear configuration.
And another object of the invention is the provision of a releasable fastener that is inexpensively manufactured.